As part of the study, a team of international researchers analysed data on the consumption of 17 key food items and nutrients related to obesity and major diseases like heart disease, stroke, type 2 diabetes, and diet-related cancers.

They looked at the changes in diets between 1990 and 2010 in countries around the world.

They looked at three different diet patterns and gave each a score.

The first was based on 10 healthy food items: fruit, vegetables, beans and legumes, nuts and seeds, whole grains, milk, total polyunsaturated fatty acids, fish, omega-3s, and dietary fibre.